WO2023106217A1

WO2023106217A1 - Composition comprising polyion complex particle

Info

Publication number: WO2023106217A1
Application number: PCT/JP2022/044490
Authority: WO
Inventors: Takehiko Kasai; Hidehiko ASANUMA; Rui Niimi; Shinobu Mitsuda
Original assignee: L'oreal
Priority date: 2021-12-08
Filing date: 2022-11-25
Publication date: 2023-06-15

Abstract

The present invention relates to a composition, preferably a cosmetic composition, and more preferably a cosmetic composition for keratin substance, comprising: (a) at least one cationic polymer; (b) at least one anionic polymer; (c) at least one non-polymeric acid or salt, or salt thereof; and (d) water, wherein the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g, and the (a) cationic polymer, the (b) anionic polymer, and the (c) non-polymeric acid or salt thereof is capable of forming at least one polyion complex particle with a particle size of less than 1000 nm. It is possible to control the polyion complex particle size without changing the molecular weight of a cationic polymer or an anionic polymer.

Description

DESCRIPTION

TITLE OF INVENTION

COMPOSITION COMPRISING POLYION COMPLEX PARTICLE

TECHNICAL FIELD

The present invention relates to a composition, preferably a cosmetic composition, and more preferably a cosmetic composition for a keratin substance, which includes a polyion complex particle.

BACKGROUND ART

A polyion complex, which can be formed with an anionic polymer and a cationic polymer, is already known.

For example, WO 2017/104221 discloses a composition which is useful for cosmetic treatments and comprises at least one polyion complex particle comprising at least one cationic polymer, at least one anionic polymer and at least one non-polymeric acid having two or more pKa values.

Also, WO 2018/230673 discloses a composition which includes such a polyion complex particle and an oil which may further include an oil-gelling agent. The oil-gelling agent is used to enhance the stability of the composition.

Furthermore, JP-A-2014-114272 discloses controlling the particle size of polyion complex particles by changing the molecular weight of a cationic polymer.

DISCLOSURE OF INVENTION

Thus, an objective of the present invention is to provide a composition including a polyion complex particle whose size can be controlled without changing the molecular weight of a cationic polymer.

The above objective of the present invention can be achieved by a composition, preferably a cosmetic composition, and more preferably a cosmetic composition for keratin substance, comprising:

(a) at least one cationic polymer;

(b) at least one anionic polymer;

(c) at least one non-polymeric acid or salt thereof; and

(d) water wherein the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g, and the (a) cationic polymer, the (b) anionic polymer, and the (c) non-polymeric acid or salt thereof is capable of forming at least one polyion complex particle with a particle size of less than 1000 nm.

The (a) cationic polymer may be selected from (co)polyamines.

The (a) cationic polymer may be selected from the group consisting of polylysine, chitosan, and a mixture thereof.

The amount of the (a) cationic polymer(s) in the composition according to the present invention may be from 0.001% to 2% by weight, preferably from 0.005% to 1.5% by weight, and more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.

The (b) anionic polymer may be selected from polysaccharides.

The (b) anionic polymer may be selected from the group consisting of hyaluronate,

carrageenan, A-carrageenan, algin, chondroitin sulfate, pectin, and a mixture thereof.

The amount of the (b) anionic polymer(s) in the composition according to the present invention may be from 0.001% to 2% by weight, preferably from 0.005% to 1.5% by weight, and more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.

The (c) non-polymeric acid may have two or more pKa values.

The (c) non-polymeric acid may be selected from the group consisting of phytic acid, citric acid, lactic acid, and a mixture thereof.

The amount of the (c) non-polymeric acid(s) or salt(s) thereof, in the composition according to the present invention may be from 0.001% to 1% by weight, preferably from 0.005% to 0.5% by weight, and more preferably from 0.01% to 0.1% by weight, relative to the total weight of the composition.

The amount of the (d) water in the composition according to the present invention may be from 60% to 97% by weight, preferably from 70% to 96% by weight, and more preferably from 80% to 95% by weight, relative to the total weight of the composition.

The pH of the composition according to the present invention may be from 3 to 9, preferably from 3.5 to 8.5, and more preferably from 4 to 8.

The present invention also relates to a cosmetic process for keratin substance, comprising applying to the keratin substance the composition according to the present invention; and drying the composition to form a cosmetic film on the keratin substance.

The present invention also relates to a use of (a) at least one cationic polymer; (b) at least one anionic polymer; and

(c) at least one non-polymeric acid or salt thereof wherein the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, and the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g, in a composition comprising (d) water, in order to forming at least one polyion complex particle comprising the (a) cationic polymer, the (b) anionic polymer, and the (c) non-polymeric acid or salt thereof with a particle size of less than 1000 nm.

BEST MODE FOR CARRYING OUT THE INVENTION

After diligent research, the inventors have discovered that it is possible to provide a composition including a polyion complex particle whose size can be controlled without changing the molecular weight of a cationic polymer.

Thus, the composition according to the present invention is a composition, preferably a cosmetic composition, and more preferably a cosmetic composition for keratin substance, comprising:

(a) at least one cationic polymer;

(b) at least one anionic polymer;

(c) at least one non-polymeric acid or salt thereof; and

The present invention can be characterized by satisfying specific conditions regarding electric charges of a cationic polymer and an anionic polymer as well as a non-polymeric acid or salt thereof in order to control the particle size of the polyion complex particle formed by the cationic polymer, the anionic polymer and the non-polymeric acid or salt thereof.

According to the present invention, it is possible to control the polyion complex particle size without changing the molecular weight of a cationic polymer or an anionic polymer. The particle size of the polyion complex particle can be controlled by the present invention to be less than 1000 nm.

As the polyion complex particle can be controlled as being “nano” size, the composition according to the present invention can be transparent or translucent, and preferably transparent.

Hereinafter, the composition and the like according to the present invention will be explained in a more detailed manner.

[Electric Charge Conditions]

According to the present invention, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, and the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g.

The “charge concentration” here means the concentration of charged (ionized) or chargeable (ionisable) functional groups of a molecule such as a cationic polymer and an anionic polymer. The charge concentration may be regarded as “charge density” or “charge equivalent”. The “charge concentration” here is an absolute value.

The charge concentration reflects the density of functional groups which can act as cations or anions in an aqueous medium such as water. As examples of functional groups which can act as cations in water, mention may be made of, amino groups and ammonium groups. As examples of functional groups which can act as anions in water, mention may be made of, sulfonic groups and phosphoric group.

The charge concentration can be calculated as follows.

Charge Concentration = (number of charged or chargeable sites of molecule)/(molecular weight of molecule with a counter ion if present) wherein if the molecule is in the form of a polymer, the molecule means a repeating unit of the polymer.

According to the present invention, the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8.

The amount of cations of the (a) cationic polymer can be calculated by multiplying the charge concentration of the (a) cationic polymer with the amount of the (a) cationic polymer.

The amount of anions of the (b) cationic polymer can be calculated by multiplying the charge concentration of the (b) anionic polymer with the amount of the (b) anionic polymer.

The ratio of the amount of cations of the (a) cationic polymer to the amount of anions of the (b) anionic polymer can be calculated by dividing the amount of cations of the (a) cationic polymer by the amount of anions of the (b) anionic polymer. The above ratio may reflect the ratio of the mole number of cationic functional groups of the (a) cationic polymer to the mole number of the anionic functional groups of the (b) anionic polymer.

According to the present invention, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5.

The amount of the anions of the (c) non-polymeric acid or salt thereof can be calculated by multiplying the charge concentration of the ingredient (c) with the amount of the (c) ingredient.

The ratio of the amount of cations of the (a) cationic polymer to the sum of the amount of anions of the (b) anionic polymer and the amount of the (c) non-polymeric acid or salt thereof can be calculated by dividing the amount of cations of the (a) cationic polymer by the sum of the amount of anions of the (b) anionic polymer and the amount of anions of the (c) non- polymeric anionic acid or salt thereof.

The above ratio may reflect the ratio of the mole number of cationic functional groups of the (a) cationic polymer to the mole number of the anionic functional groups of the (b) anionic polymer and the (c) non-polymeric acid(s) or salt(s) thereof.

[Polyion Complex]

According to the present invention, the (a) cationic polymer, the (b) anionic polymer, and the (c) non-polymeric acid or salt thereof is capable of forming at least one polyion complex particle with a particle size of less than 1000 nm.

The particle size of the polyion complex particle in the composition according to the present invention is less than 1000 nm, preferably less than 800 nm, more preferably less than 600 nm, even more preferably less than 400 nm, and in particular preferably less than 200 nm.

The particle size of the polyion complex particle in the composition according to the present invention may be 2 nm or more, preferably 4 nm or more, more preferably 6 nm or more, even more preferably 8 nm or more, and in particular preferably 10 nm or more.

This particle size can be measured by a dynamic light scattering method. The particle size can be based on a volume-average diameter.

Thus, the composition according to the present invention can include at least one polyion complex particles. Two or more different types of polyion complex particles may be used in combination. Thus, a single type of polyion complex particle or a combination of different types of polyion complex particles may be used.

The amount of the polyion complex particle(s) in the composition according to the present invention may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more, relative to the total weight of the composition. The amount of the polyion complex particle(s) in the composition according to the present invention may be 15% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less, relative to the total weight of the composition.

The amount of the polyion complex particle(s) in the composition according to the present invention may be from 0.001% to 15% by weight, preferably from 0.005% to 10% by weight, and more preferably from 0.01% to 5% by weight, relative to the total weight of the composition.

(Cationic Polymer)

The composition according to the present invention comprises (a) at least one cationic polymer. Two or more cationic polymers may be used in combination. Thus, a single type of cationic polymer or a combination of different types of cationic polymers may be used.

The (a) cationic polymer has or can have a positive charge or positive charges.

The charge concentration or charge density of the (a) cationic polymer is more than 0.71 mmol/g, preferably more than 1 mmol/g, more preferably more than 2 mmol/g, more preferably more than 3 mmol/g, more preferably more than 4 mmol/g, more preferably more than 5 mmol/g, more preferably more than 6 mmol/g, and even more preferably more than 7 mmol/g.

The molecular weight of the cationic polymer may be 1000 or more, preferably 50000 or more, more preferably 100000 or more, and even more preferably 1000000 or more.

Unless otherwise defined in the descriptions, “molecular weight” means a number-average molecular weight.

The cationic polymer may have at least one positively chargeable and/or positively charged moiety selected from the group consisting of a primary, secondary or tertiary amino group, a quaternary ammonium group, a guanidine group, a biguanide group, an imidazole group, an imino group, and a pyridyl group. The term (primary) “amino group” here means a group of -NH₂.

The cationic polymer may be a homopolymer or a copolymer. The term “copolymer” is understood to mean both copolymers obtained from two kinds of monomers and those obtained from more than two kinds of monomers, such as terpolymers obtained from three kinds of monomers.

The cationic polymer may be selected from natural and synthetic cationic polymers. Nonlimiting examples of the cationic polymers are as follows.

(1) Homopolymers and copolymers derived from acrylic or methacrylic esters and amides and comprising at least one unit chosen from units of the following formulas:

wherein:

R₁ and R₂, which may be identical or different, are chosen from hydrogen and alkyl groups comprising from 1 to 6 carbon atoms, for instance, methyl and ethyl groups;

R₃, which may be identical or different, is chosen from hydrogen and CH₃; the symbols A, which may be identical or different, are chosen from linear or branched alkyl groups comprising from 1 to 6 carbon atoms, for example, from 2 to 3 carbon atoms and hydroxyalkyl groups comprising from 1 to 4 carbon atoms;

R₄, R₅, and R₆, which may be identical or different, are chosen from alkyl groups comprising from 1 to 18 carbon atoms and benzyl groups, and in at least one embodiment, alkyl groups comprising from 1 to 6 carbon atoms; and

X is an anion derived from an inorganic or organic acid, such as metho sulphate anions and halides, for instance chloride and bromide.

The copolymers of family (1) may also comprise at least one unit derived from comonomers which may be chosen from acrylamides, methacrylamides, diacetone acrylamides, acrylamides and methacrylamides substituted on the nitrogen atom with (C₁-C₄) lower alkyl groups, groups derived from acrylic or methacrylic acids and esters thereof, vinyllactams such as vinylpyrrolidone and vinylcaprolactam, and vinyl esters.

Examples of copolymers of family (1) include, but are not limited to: copolymers of acrylamide and of dimethylaminoethyl methacrylate quatemized with dimethyl sulphate or with a dimethyl halide, copolymers of acrylamide and of methacryloyloxyethyltrimethylammonium chloride described, for example, in European Patent Application No. 0 080 976, copolymers of acrylamide and of methacryloyloxyethyltrimethylammonium methosulphate, quatemized or nonquaternized vinylpyrrolidone/dialkylaminoalkyl acrylate or methacrylate copolymers, described, for example, in French Patent Nos. 2 077 143 and 2 393 573, dimethylaminoethyl methacrylate/vinylcaprolactam/vinylpyrrolidone terpolymers, vinylpyrrolidone/methacrylamidopropyldimethylamine copolymers, quaternized vinylpyrrolidone/dimethylaminopropylmethacrylamide copolymers, and crosslinked methacryloyloxy(C₁-C₄)alkyltri(C₁-C₄)alkylammonium salt polymers such as the polymers obtained by homopolymerization of dimethylaminoethyl methacrylate quatemized with methyl chloride, or by copolymerization of acrylamide with dimethylaminoethyl methacrylate quatemized with methyl chloride, the homopolymerization or copolymerization being followed by crosslinking with a compound containing an olefinic unsaturation, for example, methylenebisacrylamide.

(2) Cationic cellulose derivatives such as cellulose ether derivatives comprising quaternary ammonium groups are described, for example, in French Patent No. 1 492 597, such as the polymers sold under the names "JR" (JR 400, JR 125, JR 30M) or "LR" (LR 400, LR 30M) by the company Union Carbide Corporation. These polymers are also defined in the CTFA dictionary as quaternary ammoniums of hydroxyethylcellulose that have reacted with an epoxide substituted with a trimethylammonium group.

(3) Cationic cellulose derivatives such as cellulose copolymers and cellulose derivatives are grafted with a water-soluble monomer of quaternary ammonium and described, for example, in U.S. Pat. No. 4,131,576, such as hydroxyalkylcelluloses, for instance, hydroxymethyl-, hydroxyethyl-, and hydroxypropylcelluloses grafted, for example, with a salt chosen from methacryloylethyltrimethylammonium, methacrylamidopropyltrimethylammonium, and dimethyldiallylammonium salts.

Commercial products corresponding to these polymers include, for example, the products sold under the name "Celquat® L 200" and "Celquat® H 100" by the company National Starch.

(4) Non-cellulose-based cationic polysaccharides described in U.S. Pat. Nos. 3,589,578 and 4,031,307, such as guar gums comprising cationic trialkylammonium groups, cationic hyaluronic acid, and dextran hydroxypropyl trimonium chloride. Guar gums modified with a salt, for example the chloride, of 2,3 -epoxypropyltrimethylammonium (guar hydroxypropyltrimonium chloride) may also be used.

Such products are sold, for instance, under the trade names JAGUAR® C13 S, JAGUAR® C15, JAGUAR® C17, and JAGUAR® C162 by the company MEYHALL.

(5) Polymers comprising piperazinyl units and divalent alkylene or hydroxyalkylene groups comprising straight or branched chains, optionally interrupted with at least one entity chosen from oxygen, sulphur, nitrogen, aromatic rings, and heterocyclic rings, and also the oxidation and/or quatemization products of these polymers. Such polymers are described, for example, in French Patent Nos. 2 162 025 and 2 280 361.

(6) Water-soluble polyamino amides prepared, for example, by polycondensation of an acidic compound with a polyamine; these polyamino amides possibly being crosslinked with an entity chosen from epihalohydrins; diepoxides; dianhydrides; unsaturated dianhydrides; bisunsaturated derivatives; bishalohydrins; bisazetidiniums; bishaloacyidiamines; bisalkyl halides; oligomers resulting from the reaction of a difunctional compound which is reactive with an entity chosen from bishalohydrins, bisazetidiniums, bishaloacyldiamines, bisalkyl halides, epihalohydrins, diepoxides, and bisunsaturated derivatives; the crosslinking agent being used in an amount ranging from 0.025 to 0.35 mol per amine group of the polyamino amide; these polyamino amides optionally being alkylated or, if they comprise at least one tertiary amine function, they may be quatemized. Such polymers are described, for example, in French Patent Nos. 2 252 840 and 2 368 508.

(7) Polyamino amide derivatives resulting from the condensation of polyalkylene polyamines with polycarboxylic acids, followed by alkylation with difunctional agents, for example, adipic acid/dialkylaminohydroxyalkyldialkylenetriamine polymers in which the alkyl group comprises from 1 to 4 carbon atoms, such as methyl, ethyl, and propyl groups, and the alkylene group comprises from 1 to 4 carbon atoms, such as an ethylene group. Such polymers are described, for instance, in French Patent No. 1 583 363. In at least one embodiment, these derivatives may be chosen from adipic acid/dimethylaminohydroxypropyldiethylenetriamine polymers.

(8) Polymers obtained by reaction of a polyalkylene polyamine comprising two primary amine groups and at least one secondary amine group, with a dicarboxylic acid chosen from diglycolic acid and saturated aliphatic dicarboxylic acids comprising from 3 to 8 carbon atoms. The molar ratio of the polyalkylene polyamine to the dicarboxylic acid may range from 0.8:1 to 1.4:1; the polyamino amide resulting therefrom being reacted with epichlorohydrin in a molar ratio of epichlorohydrin relative to the secondary amine group of the polyamino amide ranging from 0.5:1 to 1.8:1. Such polymers are described, for example, in U.S. Pat. Nos. 3,227,615 and 2,961,347.

(9) Cyclopolymers of alkyldiallylamine and cyclopolymers of dialkyldiallyl-ammonium, such as homopolymers and copolymers comprising, as the main constituent of the chain, at least one unit chosen from units of formulas (la) and (lb):

wherein: k and t, which may be identical or different, are equal to 0 or 1, the sum k+t being equal to 1 ; R₁₂ is chosen from hydrogen and methyl groups;

R₁₀ and R₁₁, which may be identical or different, are chosen from alkyl groups comprising from 1 to 6 carbon atoms, hydroxyalkyl groups in which the alkyl group comprises, for example, from 1 to 5 carbon atoms, and lower (C₁-C₄)amidoalkyl groups, or R₁₀ and R₁₁ may form, together with the nitrogen atom to which they are attached, heterocyclic groups such as piperidinyl and morpholinyl; and

Y' is an anion such as bromide, chloride, acetate, borate, citrate, tartrate, bisulphate, bisulphite, sulphate, and phosphate. These polymers are described, for example, in French Patent No. 2 080 759 and in its Certificate of Addition 2 190 406.

In one embodiment, R₁₀ and R₁₁, which may be identical or different, are chosen from alkyl groups comprising from 1 to 4 carbon atoms.

Examples of such polymers include, but are not limited to, (co)polydiallyldialkyl ammonium chloride such as the dimethyidiallylammonium chloride homopolymer sold under the name "MERQUAT® 100" by the company CALGON (and its homologues of low weight-average molecular mass) and the copolymers of diallyldimethylammonium chloride and of acrylamide sold under the name "MERQUAT® 550".

Quaternary diammonium polymers comprising at least one repeating unit of formula (II):

wherein:

R₁₃, R₁₄, R₁₅, and R₁₆, which may be identical or different, are chosen from aliphatic, alicyclic, and arylaliphatic groups comprising from 1 to 20 carbon atoms and lower hydroxyalkyl aliphatic groups, or alternatively R₁₃, R₁₄, R₁₅, and R₁₆ may form, together or separately, with the nitrogen atoms to which they are attached, heterocycles optionally comprising a second heteroatom other than nitrogen, or alternatively R₁₃, R₁₄, R₁₅, and R₁₆, which may be identical or different, are chosen from linear or branched C₁-C₆ alkyl groups substituted with at least one group chosen from nitrile groups, ester groups, acyl groups, amide groups, -CO-O-R₁₇-E groups, and -CO-NH-R17-E groups, wherein R17 is an alkylene group and E is a quaternary ammonium group;

A₁ and Bi, which may be identical or different, are chosen from polymethylene groups comprising from 2 to 20 carbon atoms, which may be linear or branched, saturated or unsaturated, and which may comprise, linked or intercalated in the main chain, at least one entity chosen from aromatic rings, oxygen, sulphur, sulphoxide groups, sulphone groups, disulphide groups, amino groups, alkylamino groups, hydroxyl groups, quaternary ammonium groups, ureido groups, amide groups, and ester groups, and

X- is an anion derived from an inorganic or organic acid; A₁, R₁₃, and R₁₅ may form, together with the two nitrogen atoms to which they are attached, a piperazine ring; if A₁ is chosen from linear or branched, saturated or unsaturated alkylene or hydroxyalkylene groups, Bi may be chosen from:

-(CH₂)_n-CO-E'-OC-(CH₂)_n- wherein E' is chosen from: a) glycol residues of formula -O-Z-O-, wherein Z is chosen from linear or branched hydrocarbon-based groups and groups of the following formulas:

-(CH₂-CH₂-O)_X-CH₂-CH₂-

-[CH₂-CH(CH₃)-O]_y-CH₂-CH(CH₃)- wherein x and y, which may be identical or different, are chosen from integers ranging from 1 to 4, which represent a defined and unique degree of polymerization, and numbers ranging from 1 to 4, which represent an average degree of polymerization; b) bis-secondary diamine residue such as piperazine derivatives; c) bis-primary diamine residues of formula -NH-Y-NH-, wherein Y is chosen from linear or branched hydrocarbon-based groups and the divalent group -CH₂-CH₂-S-S-CH₂-CH_2-; and d) ureylene groups of formula -NH-CO-NH-.

In at least one embodiment, X" is an anion such as chloride or bromide.

Polymers of this type are described, for example, in French Patent Nos. 2 320 330; 2 270 846; 2 316 271; 2 336 434; and 2 413 907 and U.S. Pat. Nos. 2,273,780; 2,375,853; 2,388,614; 2,454,547; 3,206,462; 2,261,002; 2,271,378; 3,874,870; 4,001,432; 3,929,990; 3,966,904; 4,005,193; 4,025,617; 4,025,627; 4,025,653; 4,026,945; and 4,027,020.

Non-limiting examples of such polymers include those comprising at least one repeating unit of formula (III):

wherein

R₁₃, R₁₄, R₁₅, and R₁₆, which may be identical or different, are chosen from alkyl and hydroxyalkyl groups comprising from 1 to 4 carbon atoms, n and p, which may be identical or different, are integers ranging from 2 to 20, and X- is an anion derived from an inorganic or organic acid.

(11) Poly quaternary ammonium polymers comprising units of formula (IV):

wherein:

R₁₈, R₁₉, R₂₀, and R₂₁, which may be identical or different, are chosen from hydrogen, methyl groups, ethyl groups, propyl groups, p-hydroxyethyl groups, β-hydroxypropyl groups, - CH₂CH₂(OCH₂CH₂)_pOH groups, wherein p is chosen from integers ranging from 0 to 6, with the proviso that R₁₈, R₁₉, R₂₀, and R₂₁ are not simultaneously hydrogen, r and s, which may be identical or different, are chosen from integers ranging from 1 to 6, q is chosen from integers ranging from 0 to 34, X’ is an anion such as a halide, and

A is chosen from radicals of dihalides and -CH₂-CH₂-O-CH₂-CH₂-.

Such compounds are described, for instance, in European Patent Application No. 0 122 324.

(12) Quaternary polymers of vinylpyrrolidone and of vinylimidazole.

Other examples of suitable cationic polymers include, but are not limited to, cationic proteins and cationic protein hydrolysates, polyalkyleneimines, such as polyethyleneimines, polymers comprising units chosen from vinylpyridine and vinylpyridinium units, condensates of polyamines and of epichlorohydrin, quaternary polyureylenes, and chitin derivatives.

According to one embodiment of the present invention, the at least one cationic polymer is chosen from cellulose ether derivatives comprising quaternary ammonium groups, such as the products sold under the name "JR 400" by the company UNION CARBIDE CORPORATION, cationic cyclopolymers, for instance, the homo-polymers and copolymers of dimethyldiallylammonium chloride sold under the names MERQUAT® 100, MERQUAT® 550, and MERQUAT® S by the company CALGON, guar gums modified with a 2,3 -epoxypropyltrimethylammonium salt, and quaternary polymers of vinylpyrrolidone and of vinylimidazole.

(13) Polyamines

As the cationic polymer, it is also possible to use (co)polyamines, which may be homopolymers or copolymers, with a plurality of amino groups. The amino group may be a primary, secondary, tertiary or quaternary amino group. The amino group may be present in a polymer backbone or a pendent group, if present, of the (co)polyamines.

As example of the (co)polyamines, mention may be made of chitosan, (co)polyallylamines, (co)polyvinylamines, (co)polyanilines, (co)polyvinylimidazoles, (co)poly dimethylaminoethylenemethacrylates, (co)polyvinylpyridines such as (co)poly-l- methyl-2-vinylpyridines, (co)polyimines such as (co) polyethyleneimines, (co)polypyridines such as (co)poly(quatemary pyridines), (co)polybiguanides such as (co)polyaminopropyl biguanides, (co)polylysines, (co)polyomithines, (co)polyarginines, (co)polyhistidines, aminodextrans, aminocelluloses, amino(co)polyvinylacetals, and salts thereof. As the (co)polyamines, it is preferable to use (co)polylysines. Polylysine is well known. Polylysine can be a natural homopolymer of L-lysine that can be produced by bacterial fermentation. For example, polylysine can be s-Poly-L-lysine, typically used as a natural preservative in food products. Polylysine is a polyelectrolyte which is soluble in polar solvents such as water, propylene glycol and glycerol. Polylysine is commercially available in various forms, such as poly D-lysine and poly L-lysine. Polylysine can be in salt and/or solution form.

(14) Cationic Polyaminoacids

As the cationic polymer, it may be possible use cationic polyaminoacids, which may be cationic homopolymers or copolymers, with a plurality of amino groups and carboxyl groups. The amino group may be a primary, secondary, tertiary or quaternary amino group. The amino group may be present in a polymer backbone or a pendent group, if present, of the cationic polyaminoacids. The carboxyl group may be present in a pendent group, if present, of the cationic polyaminoacids.

As examples of the cationic polyaminoacids, mention may be made of cationized collagen, cationized gelatin, steardimoium hydroxyprolyl hydrolyzed wheat protein, cocodimonium hydroxypropyl hydrolyzed wheat protein, hydroxypropyltrimonium hydrolyzed conchiolin protein, steardimonium hydroxypropyl hydrolyzed soy protein, hydroxypropyltrimonium hydrolyzed soy protein, cocodimonium hydroxypropyl hydrolyzed soy protein, and the like.

It may be preferable that the (a) cationic polymer be selected from (co)polyamines.

It may be more preferable that the (a) cationic polymer be selected from the group consisting of polylysine, chitosan, and a mixture thereof.

The amount of the (a) cationic polymer(s) in the composition according to the present invention may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more, relative to the total weight of the composition.

The amount of the (a) cationic polymer(s) in the composition according to the present invention may be 2% by weight or less, preferably 1.5% by weight or less, and more preferably 1% by weight or less, relative to the total weight of the composition.

(Anionic Polymer)

The composition according to the present invention comprises (b) at least one anionic polymer. Two or more anionic polymers may be used in combination. Thus, a single type of anionic polymer or a combination of different types of anionic polymers may be used.

The (b) anionic polymer has or can have a negative charge or negative charges. The charge concentration or charge density of the (b) anionic polymer is more than 2.04 mmol/g, preferably more than 2.20 mmol/g, and more preferably more than 2.40 mmol/g.

The charge concentration or charge density of the (b) anionic polymer is less than 10.64 mmol/g, preferably less than 8.00 mmol/g, and more preferably less than 6.00 mmol/g.

It is preferable that the charge concentration or charge density of the (b) anionic polymer be less than 5.00 mmol/g, more preferably less than 4.70 mmol/g, and even more preferably less than 4.40 mmol/g.

The charge concentration or charge density of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g, preferably more than 2.20 mmol/g and less than 8.00 mmol/g, and more preferably more than 2.40 mmol/g and less than 6.00 mmol/g.

It is preferable that the charge concentration or charge density of the (b) anionic polymer be more than 2.04 mmol and less than 5.00 mmol/g, more preferably more than 2.20 mmol/g and less than 4.70 mmol/g, and even more preferably more than 2.40 mmol/g and less than 4.40 mmol/g.

The molecular weight of the anionic polymer may be 1,000 or more, preferably 10,000 or more, more preferably 50,000 or more, and even more preferably 100,000 or more.

The anionic polymer may have at least one negatively chargeable and/or negatively charged moiety selected from the group consisting of a sulfuric group, a sulfate group, a sulfonic group, a sulfonate group, a phosphoric group, a phosphate group, a phosphonic group, a phosphonate group, a carboxylic group, and a carboxylate group.

The anionic polymer may be a homopolymer or a copolymer. The term “copolymer” is understood to mean both copolymers obtained from two kinds of monomers and those obtained from more than two kinds of monomers, such as terpolymers obtained from three kinds of monomers.

The anionic polymer may be selected from natural and synthetic anionic polymers.

The anionic polymer may comprise at least one hydrophobic chain.

The anionic polymer, which may comprise at least one hydrophobic chain, may be obtained by copolymerization of a monomer (a) chosen from carboxylic acids comprising α,β-ethylenic unsaturation (monomer a’) and 2-acrylamido-2-methylpropanesulphonic acid (monomer a”) with a non-surface-active monomer (b) comprising an ethylenic unsaturation other than (a) and/or a monomer (c) comprising an ethylenic unsaturation resulting from the reaction of an acrylic monomer comprising an α,β-monoethylenic unsaturation or of an isocyanate monomer comprising a monoethylenic unsaturation with a monohydric nonionic amphiphilic component or with a primary or secondary fatty amine.

Thus, the anionic polymer with at least one hydrophobic chain may be obtained by two synthetic routes:

- either by copolymerization of the monomers (a’) and (c), or (a’), (b) and (c), or (a”) and (c), or (a”), (b) and (c), - or by modification (and in particular esterification or amidation) of a copolymer formed from the monomers (a’) or from the monomers (a’) and (b), or (a”) and (b), by a monohydric nonionic amphiphilic compound or a primary or secondary fatty amine.

Mention may in particular be made, as 2-acrylamido-2-methylpropanesulphonic acid copolymers, of those disclosed in the article “Micelle formation of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate and nonionic surfactant macromonomer in water as studied by fluorescence and dynamic light scattering - Macromolecules, 2000, Vol. 33, No. 10 - 3694-3704” and in applications EP-A-0 750 899 and EP-A-1 069 172.

The carboxylic acid comprising an α,β-monoethylenic unsaturation constituting the monomer (a’) can be chosen from numerous acids and in particular from acrylic acid, methacrylic acid, crotonic acid, itaconic acid and maleic acid. It is preferably acrylic or methacrylic acid.

The copolymer can comprise a monomer (b) comprising a monoethylenic unsaturation which does not have a surfactant property. The preferred monomers are those which give waterinsoluble polymers when they are homopolymerized. They can be chosen, for example, fromC₁-C₄ alkyl acrylates and methacrylates, such as methyl acrylate, ethyl acrylate, butyl acrylate or the corresponding methacrylates. The more particularly preferred monomers are methyl acrylate and ethyl acrylate. The other monomers which can be used are, for example, styrene, vinyltoluene, vinyl acetate, acrylonitrile and vinylidene chloride. Unreactive monomers are preferred, these monomers being those in which the single ethylenic group is the only group which is reactive under the polymerization conditions. However, monomers that comprise groups which react under the effect of heat, such as hydroxyethyl acrylate, can optionally be used.

The monomer (c) is obtained by reaction of an acrylic monomer comprising α,β- monoethylenic unsaturation, such as (a), or of an isocyanate monomer comprising monoethylenic unsaturation with a monohydric nonionic amphiphilic compound or a primary or secondary fatty amine.

The monohydric nonionic amphiphilic compounds or the primary or secondary fatty amines used to produce the nonionic monomer (c) are well known. The monohydric nonionic amphiphilic compounds are generally alkoxylated hydrophobic compounds comprising an alkylene oxide forming the hydrophilic part of the molecule. The hydrophobic compounds are generally composed of an aliphatic alcohol or an alkylphenol, in which compounds a carbonaceous chain comprising at least six carbon atoms constitutes the hydrophobic part of the amphiphilic compound.

The preferred monohydric nonionic amphiphilic compounds are compounds having the following formula (V):

R-(OCH₂CHR’)_m-(OCH₂CH₂)_n-OH (V) in which R is chosen from alkyl or alkylene groups comprising from 6 to 30 carbon atoms and alkylaryl groups having alkyl radicals comprising from 8 to 30 carbon atoms, R’ is chosen from alkyl groups comprising from 1 to 4 carbon atoms, n is a mean number ranging from approximately 1 to 150 and m is a mean number ranging from approximately 0 to 50, provided that n is at least as great as m. Preferably, in the compounds of formula (V), the R group is chosen from alkyl groups comprising from 12 to 26 carbon atoms and alkylphenyl groups in which the alkyl group is C₈-C₁₃; the R’ group is the methyl group; m = 0 and n = 1 to 25.

The preferred primary and secondary fatty amines are composed of one or two alkyl chains comprising from 6 to 30 carbon atoms.

The monomer used to form the nonionic urethane monomer (c) can be chosen from highly varied compounds. Use may be made of any compound comprising a copolymerizable unsaturation, such as an acrylic, methacrylic or allylic unsaturation. The monomer (c) can be obtained in particular from an isocyanate comprising a monoethyl enic unsaturation, such as, in particular, a,a-dimethyl-m-isopropenylbenzyl isocyanate.

The monomer (c) can be chosen in particular from acrylates, methacrylates or itaconates of oxyethylenated (1 to 50 EO) C₆-C₃₀ fatty alcohol, such as steareth-20 methacrylate, oxyethylenated (25 EO) behenyl methacrylate, oxyethylenated (20 EO) monocetyl itaconate, oxyethylenated (20 EO) monostearyl itaconate or the acrylate modified by polyoxyethylenated (25 EO) C₁₂-C₂₄ alcohols and from dimethyl-m-isopropenylbenzyl isocyanates of oxyethylenated (1 to 50 EO) C₆-C₃₀ fatty alcohol, such as, in particular, the dimethyl-m-isopropenylbenzyl isocyanate of oxyethylenated behenyl alcohol.

According to a specific embodiment of the present invention, the anionic polymer is chosen from acrylic terpolymers obtained from (a) a carboxylic acid comprising an α,β-ethylenic unsaturation, (b) a non-surface-active monomer comprising an ethylenic unsaturation other than (a), and (c) a nonionic urethane monomer which is the reaction product of a monohydric nonionic amphiphilic compound with an isocyanate comprising a monoethylenic unsaturation.

Mention may in particular be made, as anionic polymers comprising at least one hydrophobic chain, of the acrylic acid/ethyl acrylate/alkyl acrylate terpolymer, such as the product as a 30% aqueous dispersion sold under the name Acusol 823 by Rohm & Haas; the acrylates/steareth-20 methacrylate copolymer, such as the product sold under the name Aculyn 22 by Rohm & Haas; the (meth)acrylic acid/ethyl acrylate/oxyethylenated (25 EO) behenyl methacrylate terpolymer, such as the product as an aqueous emulsion sold under the name Aculyn 28 by Rohm & Haas; the acrylic acid/oxyethylenated (20 EO) monocetyl itaconate copolymer, such as the product as a 30% aqueous dispersion sold under the name Structure 3001 by National Starch; the acrylic acid/oxyethylenated (20 EO) monostearyl itaconate copolymer, such as the product as a 30% aqueous dispersion sold under the name Structure 2001 by National Starch; the acrylates/acrylate modified by polyoxyethylenated (25 EO) C₁₂-C₂₄ alcohol copolymer, such as the 30-32% copolymer latex sold under the name Synthalen W2000 by 3 V SA; or the methacrylic acid/methyl acrylate/dimethyl-meta- isopropenylbenzyl isocyanate of ethoxylated behenyl alcohol terpolymer, such as the product as a 24% aqueous dispersion and comprising 40 ethylene oxide groups disclosed in the document EP -A-0 173 109.

The anionic polymers may also be Polyester-5, such as the product sold under the name of Eastman AQ™ 55 S Polymer by EASTMAN CHEMICAL having a chemical formula below.

A: dicarboxylic acid moiety

G: glycol moiety

SO₃-Na⁺: sodium sulfo group

OH: hydroxyl group

It may be preferable that the anionic polymer be selected from the group consisting of polysaccharides such as carrageenan (e.g, i-carrageenan, and A-carrageenan), pectin, alginic acid (algin), hyaluronic acid, and cellulose polymers (e.g., carboxymethylcellulose), anionic (co)polyaminoacids such as (co)polyglutamic acids, (co)poly(meth)acrylic acids, (co)polyamic acids, (co)polystyrene sulfonate, (co)poly(vinyl sulfate), dextran sulfate, chondroitin sulfate, (co)polymaleic acids, (co)polyfumaric acids, maleic acid (co)polymers, and salts thereof.

The maleic acid copolymer may comprise one or more maleic acid comonomers, and one or more comonomers chosen from vinyl acetate, vinyl alcohol, vinylpyrrolidone, olefins comprising from 2 to 20 carbon atoms, and styrene.

Thus, the "maleic acid copolymer" is understood to mean any polymer obtained by copolymerization of one or more maleic acid comonomers and of one or more comonomers chosen from vinyl acetate, vinyl alcohol, vinylpyrrolidone, olefins comprising from 2 to 20 carbon atoms, such as octadecene, ethylene, isobutylene, diisobutylene or isooctylene, and styrene, the maleic acid comonomers optionally being partially or completely hydrolysed. Use will preferably be made of hydrophilic polymers, that is to say polymers having a solubility of water of greater than or equal to 2 g/1.

In an advantageous aspect of the present invention, the maleic acid copolymer may have a molar fraction of maleic acid units of between 0.1 and 1 and preferably between 0.4 and 0.9.

The weight-average molar mass of the maleic acid copolymer may be between 1 ,000 and 500,000 and preferably between 1,000 and 50,000.

It is preferable that the maleic acid copolymer be a styrene/maleic acid copolymer, and more preferably sodium styrene/maleic acid copolymer.

Use will preferably be made of a copolymer of styrene and of maleic acid in a 50/50 ratio.

Use may be made, for example, of the styrene/maleic acid (50/50) copolymer, in the form of an ammonium salt at 30% in water, sold under the reference SMA1000H® by Cray Valley or the styrene/maleic acid (50/50) copolymer, in the form of a sodium salt at 40% in water, sold under the reference SMAlOOOHNa® by Cray Valley.

It may be preferable that the anionic polymer be selected from polysaccharides.

It may be more preferable that the anionic polymer be selected from the group consisting of hyaluronate, i-carrageenan, A-carrageenan, algin, chondroitin sulfate, pectin, and a mixture thereof.

The amount of the (b) anionic polymer(s) in the composition according to the present invention may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more, relative to the total weight of the composition. The amount of the (b) anionic polymer(s) in the composition according to the present invention may be 2% by weight or less, preferably 1.5% by weight or less, and more preferably 1% by weight or less, relative to the total weight of the composition.

(Non-Polymeric Acid or Salt Thereof)

The composition according to the present invention comprises (c) at least one non-polymeric acid or salt thereof. Two or more non-polymeric acid or salts may be used in combination. Thus, a single type of non-polymeric acid or salt thereof or a combination of different types of non-polymeric acids or salts thereof may be used.

The term “non-polymeric” here means that the acid is not obtained by polymerizing two or more monomers. Therefore, the non-polymeric acid does not correspond to an acid obtained by polymerizing two or more monomers such as polyacrylic acids.

The term “salt” here means a salt formed by addition of suitable base(s) to the non-polymeric acid, which may be obtained from a reaction with the non-polymeric acid with the base(s) according to methods known to those skilled in the art. As the salt, mention may be made of metal salts, for example salts with alkaline metal such as Na and K, and salts with alkaline earth metal such as Mg and Ca, and ammonium salts.

It is preferable that the molecular weight of the (c) non-polymeric acid or salt thereof be less than 1000, preferably 900 or less, and more preferably 800 or less.

The (c) non-polymeric acid or salt thereof can be included in the polyion complex particle.

The (c) non-polymeric acid or salt thereof may be an organic or inorganic acid or salt thereof, preferably an organic acid or salt thereof, and more preferably a hydrophilic or water-soluble organic acid or salt thereof.

The (c) non-polymeric acid may have at least one acid groups selected from the group consisting of a carboxylic group, a sulfuric group, a sulfonic group, a phosphoric group, a phosphonic group, and a mixture thereof.

The (c) non-polymeric acid may be monovalent.

The monovalent non-polymeric acid may be selected from monocarboxylic acids, preferably hydroxyl acids, and more preferably alpha-hydroxy acids. As the alpha-hydroxy acids, mention may be made of, for example, lactic acid and glycolic acid.

The (c) non-polymeric acid may be divalent.

It may be preferable that the (c) non-polymeric acid have two or more pKa values. The pKa value (acid dissociation constant) is well known to those skilled in the art, and should be determined at a constant temperature such as 25°C. The (c) non-polymeric acid having two or more pKa values or salt thereof can function as a crosslinker for the cationic polymer.

The (c) non-polymeric acid having two or more pKa values may be selected from the group consisting of dicarboxylic acids, disulfonic acids, and diphosphoric acids, and a mixture thereof.

The (c) non-polymeric acid having two or more pKa values or salt(s) thereof may be selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, malic acid, citric acid, aconitic acid, oxaloacetic acid, tartaric acid, and salts thereof; aspartic acid, glutamic acid, and salts thereof; terephthalylidene dicamphor sulfonic acid or salts thereof (Mexoryl SX), Benzophenone-9; phytic acid, and salts thereof; Red 2 (Amaranth), Red 102 (New Coccine), Yellow 5 (Tartrazine), Yellow 6 (Sunset Yellow FCF), Green 3 (Fast Green FCF), Blue 1 (Brilliant Blue FCF), Blue 2 (Indigo Carmine), Red 201 (Lithol Rubine B), Red 202 (Lithol Rubine BCA), Red 204 (Lake Red CBA), Red 206 (Lithol Red CA), Red 207 (Lithol Red BA), Red 208 (Lithol Red SR), Red 219 (Brilliant Lake Red R), Red 220 (Deep Maroon), Red 227 (Fast Acid Magenta), Yellow 203 (Quinoline Yellow WS), Green 201 (Alizanine Cyanine Green F), Green 204 (Pyranine Cone), Green 205 (Light Green SF Yellowish), Blue 203 (Patent Blue CA), Blue 205 (Alfazurine FG), Red 401 (Violamine R), Red 405 (Permanent Re F5R), Red 502 (Ponceau 3R), Red 503 (Ponceau R), Red 504 (Ponceau SX), Green 401 (Naphtol Green B), Green 402 (Guinea Green B), and Black 401 (Naphtol Blue Black); folic acid, ascorbic acid, erythorbic acid, and salts thereof; cystine and salts thereof; EDTA and salts thereof; glycyrrhizin and salts thereof; and a mixture thereof.

It may be preferable that the (c) non-polymeric acid be selected from the group consisting of phytic acid, citric acid, lactic acid, and a mixture thereof.

The amount of the (c) non-polymeric acid(s) or salt(s) thereof in the composition according to the present invention may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more, relative to the total weight of the composition.

The amount of the (c) non-polymeric acid(s) or salt(s) thereof in the composition according to the present invention may be 1% by weight or less, preferably 0.5% by weight or less, and more preferably 0.1% by weight or less, relative to the total weight of the composition.

The amount of the (c) non-polymeric acid(s) or salt(s) thereof in the composition according to the present invention may be from 0.001% to 1% by weight, preferably from 0.005% to 0.5% by weight, and more preferably from 0.01% to 0.1% by weight, relative to the total weight of the composition.

[Water]

The composition according to the present invention comprises (d) water.

The (d) water can form an aqueous phase of the composition according to the present invention. The amount of the (d) water may be 60% by weight or more, preferably 70% by weight or more, and more preferably 80% by weight or more, relative to the total weight of the composition.

The amount of the (d) water may be 97% by weight or less, preferably 96% by weight or less, and more preferably 95% by weight or less, relative to the total weight of the composition.

The amount of the (d) water may be from 60% to 97% by weight, preferably from 70% to 96% by weight, and more preferably from 80% to 95% by weight, relative to the total weight of the composition.

[pH]

At a pH of from 3 to 9, the polyion complex can be very stable.

The pH of the composition according to the present invention may be adjusted by adding at least one alkaline agent and/or at least one acid, other than the (c) non-polymeric acid, to be incorporated into the polyion complex. The pH of the composition according to the present invention may also be adjusted by adding at least one buffering agent.

(Alkaline Agent)

The composition according to the present invention may comprise at least one alkaline agent. Two or more alkaline agents may be used in combination. Thus, a single type of alkaline agent or a combination of different types of alkaline agents may be used.

The alkaline agent may be an inorganic alkaline agent. It is preferable that the inorganic alkaline agent be selected from the group consisting of ammonia; alkaline metal hydroxides; alkaline earth metal hydroxides; alkaline metal phosphates and monohydrogenophosphates such as sodium phosphate or sodium monohydrogen phosphate.

As examples of the inorganic alkaline metal hydroxides, mention may be made of sodium hydroxide and potassium hydroxide. As examples of the alkaline earth metal hydroxides, mention may be made of calcium hydroxide and magnesium hydroxide. As an inorganic alkaline agent, sodium hydroxide is preferable.

The alkaline agent may be an organic alkaline agent. It is preferable that the organic alkaline agent be selected from the group consisting of monoamines and derivatives thereof; diamines and derivatives thereof; polyamines and derivatives thereof; basic amino acids and derivatives thereof; oligomers of basic amino acids and derivatives thereof; polymers of basic amino acids and derivatives thereof; urea and derivatives thereof; and guanidine and derivatives thereof.

As examples of the organic alkaline agents, mention may be made of alkanolamines such as mono-, di- and tri-ethanolamine, and isopropanolamine; urea, guanidine and their derivatives; basic amino acids such as lysine, ornithine or arginine; and diamines such as those described in the structure below:

wherein R denotes an alkylene such as propylene optionally substituted by a hydroxyl or a C₁- C₄ alkyl radical, and R₁, R₂, R₃ and R₄ independently denote a hydrogen atom, an alkyl radical or a C₁-C₄ hydroxyalkyl radical which may be exemplified by 1,3 -propanediamine and derivatives thereof. Arginine, urea and monoethanolamine are preferable.

The alkaline agent(s) may be used in a total amount of from 0.01% to 10% by weight, preferably from 0.05% to 5% by weight, more preferably from 0.1% to 1% by weight, relative to the total weight of the composition, depending on their solubility.

(Acid)

The composition according to the present invention may comprise at least one acid other than the (d) acid to be incorporated into the (a) particle. Two or more acids may be used in combination. Thus, a single type of acid or a combination of different types of acids may be used.

As the acid, mention may be made of any inorganic or organic acids, preferably inorganic acids, which are commonly used in cosmetic products. A monovalent acid and/or a polyvalent acid may be used. A monovalent acid such as citric acid, lactic acid, sulfuric acid, phosphoric acid and hydrochloric acid (HC1) may be used. Lactic acid maybe preferable.

The acid(s) may be used in a total amount of from 0.01% to 10% by weight, preferably from 0.05% to 5% by weight, more preferably from 0.1% to 1% by weight, relative to the total weight of the composition, depending on their solubility.

(Buffering Agent)

The composition according to the present invention may comprise at least one buffering agent. Two or more buffering agents may be used in combination. Thus, a single type of buffering agent or a combination of different types of buffering agents may be used.

As the buffering agent, mention may be made of an acetate buffer (for example, acetic acid + sodium acetate), a phosphate buffer (for example, sodium dihydrogen phosphate + di-sodium hydorogen phosphate), a citrate buffer (for example, citric acid + sodium citrate), a borate buffer (for example, boric acid + sodium borate), a tartrate buffer (for example, tartaric acid + sodium tartrate dihydrate), Tris buffer (for example, tris(hydroxymethyl)aminomethane), Hepes buffer (4-(2-hydroxyethyl)-l -piperazineethanesulfonic acid).

[Optional Additives]

Since the composition according to the present invention comprises (d) water, the composition according to the present invention can comprise at least one aqueous phase.

The aqueous phase may comprise at least one C₂-C₆ monohydric alcohol. Two or more C₂-C₆ monohydric alcohols may be used in combination. The C₂-C₆ monohydric alcohol suitable for the present invention may comprise from 2 to 5 carbon atoms, preferably from 2 to 4 carbon atoms, such as ethanol, isopropanol, propanol or butanol.

Ethanol and isopropanol, and preferably ethanol, are very particularly suitable for the present invention.

The amount of the C₂-C₆ monohydric alcohol in the composition according to the present invention may be 20% by weight or less, preferably 15% by weight or less, and more preferably 10% by weight or less, relative to the total weight of the composition. On the other hand, the amount of the C₂-C₆ monohydric alcohol in the composition according to the present invention is 5% by weight or more, preferably 6% by weight or more, and more preferably 7% by weight or more, relative to the total weight of the composition. For example, the amount of the C₂-C₆ monohydric alcohol may be from 5% to 20% by weight, preferably from 6% to 15% by weight, and more preferably from 7% to 10% by weight, in relation to the total weight of the composition.

The aqueous phase may comprise polyhydric alcohols containing 2 to 8 carbon atoms such as propylene glycol, ethylene glycol, 1,3 -butylene glycol, dipropylene glycol, diethylene glycol, pentyleneglycol, hexyleneglycol, glycerin, and mixtures thereof.

The amount of the polyhydric alcohol(s) such as glycols, if present} in the aqueous phase according to the present invention may range from 0.1% to 15% by weight, preferably from 0.5% to 12% by weight, and more preferably from 1% to 8% by weight, relative to the total weight of the composition.

The composition according to the present invention may comprise, in addition to the aforementioned components, components typically employed in cosmetics, for example, surfactants or emulsifiers, preservatives such as phenoxyethanol and caprylyl glycol, organic non-volatile solvents, natural extracts derived from vegetables, and the like, within a range which does not impair the effects of the present invention.

It is preferable that the composition according to the present invention comprise no pigments or dyes.

The composition according to the present invention may comprise the above optional additive(s) in an amount of from 0.01% to 50% by weight, preferably from 0.05% to 30% by weight, and more preferably from 0.1% to 10% by weight, relative to the total weight of the composition.

However, the composition according to the present invention may include a very limited amount of surfactant(s) or emulsifier(s). The amount of the surfactant(s) or emulsifier(s) in the composition according to the present invention may be 1% by weight or less, preferably 0.1% by weight or less, and more preferably 0.01% by weight or less, relative to the total weight of the composition. It is in particular preferable that the composition according to the present invention include no surfactant or emulsifier.

[Preparation]

The composition according to the present invention can be prepared by mixing the essential ingredient(s) as explained above, and optional ingredient(s), if necessary, as explained above.

The method and means to mix the above essential and optional ingredients are not limited. Any conventional method and means can be used to mix the above essential and optional ingredients to prepare the composition according to the present invention.

[Form]

The form of the composition according to the present invention is not limited. Thus, the composition according to the present invention may be in the form of a solution, a gel, or an emulsion.

The composition according to the present invention may be transparent.

The transparency may be measured by measuring the turbidity (for example, turbidity can be measured with a 2100Q (marketed by Each Company) having a round cell (25 mm in diameter and 60 mm height) and a tungsten filament lamp which can emit visible light (between 400 and 800 nm, preferably from 400 to 500 nm). The measurement can be performed on the undiluted composition. The blank may be determined with distilled water.

The composition according to the present invention may have a turbidity of 250 NTU or less, preferably 150 NTU or less, and more preferably 50 NTU or less.

[Process and Use]

The present invention also relates to a cosmetic process for keratin substance, comprising: applying to the keratin substance the composition according to the present invention; and drying the composition to form a cosmetic film on the keratin substance, and a process for preparing a film, preferably a cosmetic film, comprising: applying onto keratin substance, the composition according to the present invention; and drying the composition.

Keratin substance here means a material containing keratin as a main constituent element, and examples thereof include the skin, scalp, nails, lips, hair, and the like.

Furthermore, the present invention also relates to a film, preferably a cosmetic film, comprising at least one polyion complex comprising:

(a) at least one cationic polymer;

(b) at least one anionic polymer; and

(c) at least one non-polymeric acid or salt thereof, wherein the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, and the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g.

The present invention may also relate to a use of the composition according to the present invention for the preparation of a cosmetic film on keratin substance.

The cosmetic process here means a non-therapeutic cosmetic method for caring keratin substance.

The above film, preferably the cosmetic film, is resistant to water with a pH of 7 or less, and is removable with water with a pH of more than 7, preferably 8 or more, and more preferably 9 or more.

In other words, the above film, preferably the cosmetic film, can be water-resistant under neutral or acidic conditions such as a pH of 7 or less, preferably in a range of 6 or more and 7 or less, and more preferably in a range of 5 or more and 7 or less, while the above film preferably the cosmetic film, can be removed under alkaline conditions such as a pH of more than 7, preferably 8 or more, and more preferably 9 or more. The upper limit of the pH is preferably 13, more preferably 12, and even more preferably 11.

Accordingly, the above film, preferably the cosmetic film, can be water-resistant, and it can therefore remain on keratin substance such as skin even if the surface of the keratin substance is wet due to, for example sweat and rain. On the other hand, the above film, preferably the cosmetic film, can be easily removed from keratin substance such as skin under alkaline conditions. Therefore, the above film, preferably the cosmetic film, is difficult to remove with water, while it can be easily removed with, for example, a soap which can provide alkaline conditions.

Furthermore, the above film may have cosmetic effects such as absorbing or adsorbing malodor, changing the appearance of keratin substance such as skin, changing the feel to the touch of the keratin substance, and/or protecting the keratin substance from, for example, dirt or pollutant, due to the properties of the polyion complex in the film, even if the film does not include any cosmetic active ingredient.

The present invention also relates to a use of

(a) at least one cationic polymer;

(b) at least one anionic polymer; and

The explanations regarding the above (a) to (d) for the composition according to the present invention can apply to those in the use according to the present invention.

EXAMPLES

The present invention will be described in a more detailed manner by way of examples. However, they should not be construed as limiting the scope of the present invention.

Examples 1-1 to 1-6 and Comparative Example 1-1 to 1-13

[Preparation]

Compositions according to Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-13 were prepared by mixing the ingredients shown in Tables 1 to 3. The amount of each ingredient used in the above preparations are shown in Tables 1 to 3. The numerical values for the amounts of the ingredients shown in Tables 1 to 3 are all based on “% by weight” as raw materials.

[Evaluations]

(Charge Concentration)

The charge concentration of each cationic or anionic ingredient was calculated in accordance with the following formula:

Charge Concentration [mmol/g] = (number of charged or chargeable sites of molecule)/(molecular weight of molecule with counter ion if present) wherein if the molecule is in the form of a polymer, the molecule means a repeating unit of the polymer.

For example, if the molecule is phytic acid, the number of charged sites of phytic acid at pH 5 can be determined as -6 because it is known that 6 acid groups in phytic acid has a pKa value of around 1.84 (cf. Organic Synthetic Chemistry, Vol. 25, Number 2, pp. 167-179 (1967)). Since the molecular weight of phytic acid is 660, the charge concentration of phytic acid can be calculated as -6/660= -0.00909 = -9.09 [mmol/g] .

On the other hand, for example, if the molecule is poly-ε-lysine, the number of chargeable sites of poly-s-lysine can be determined as 1 because the repeating unit of poly-ε-lysine can be represented as follows. The primary amino group is charged under acidic conditions.

Since the molecular weight of the above repeating unit is 128, the charge concentration of poly-s-lysine can be calculated as 1/128 = 0.00781 = +7.81 [mmol/g].

Please refer to the “Charge Concentration” column in Tables 1-3. The values in the “Charge Concentration” column are absolute values.

(Polycation)

The amount of cations of a cationic polymer was determined by multiplying the charge concentration of the cationic polymer with the amount of the cationic polymer.

The results are shown in the “Polycation” line in Tables 1-3.

(Polyanion)

The amount of anions of an anionic polymer was determined by multiplying the charge concentration of the anionic polymer with the amount of the anionic polymer.

The results are shown in the “Polyanion” line in Tables 1-3. (Low Mw Anion)

The amount of anions of a non-polymeric (low molecular weight) anionic ingredient was determined by multiplying the charge concentration of the non-polymeric anionic ingredient with the amount of the non-polymeric anionic ingredient.

The results are shown in the “Low Mw Anion” line in Tables 1-3.

(Polycation/Polyanion Ratio)

The ratio of the amount of cations of the cationic polymer to the amount of anions of the anionic polymer was determined by dividing the amount of cations of the cationic polymer by the amount of anions of the anionic polymer.

The results are shown in the “Polycation/Polyanion Ratio” line in Tables 1-3.

{Polycation/(Polyanion+Low Mw Anion) Ratio}

The ratio of the amount of cations of a cationic polymer to the sum of the amount of anions of an anionic polymer and the amount of anions of a non-polymeric anionic ingredient was determined by dividing the amount of cations of the cationic polymer by the sum of the amount of anions of the anionic polymer and the amount of anions of the non-polymeric anionic ingredient.

The results are shown in the “Polycation/(Polyanion+Low Mw Anion) Ratio” line in Tables 1-3.

(Appearance)

The appearance of each of the compositions according to Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-13 were visually observed. The results of the visual observation were categorized as follows.

U: Uniform (the appearance was uniform)

A: Agglomerates (the appearance was not uniform due to agglomerates)

The results are shown in Tables 1-3.

The compositions according to Examples 1-1 to 1-6 had uniform appearance, while the compositions according to Comparative Examples 1-1 to 1-13 had non-uniform appearance due to agglomerates present in the compositions.

(Transparency)

The turbidity of each of the compositions according to Examples 1-1 to 1-6 was measured at room temperature (25°C) by using a trubidimeter (2100Q portable, Hach Company).

The results are shown in Tables 1-3 as “NTU”. The smaller the NTU value is, the more transparent the composition is. The compositions according to Examples 1-1 to 1-6 were transparent, while the compositions according to Comparative Examples 1-1 to 1-13 were not transparent, and the turbidity thereof was therefore not tested.

(Particle Size)

A particle size analyzer (Dynamic Light Scattering, ELSZ2000, Otsuka) was used to determine the size of the particle in the compositions according to Examples 1-1 to 1-6 at room temperature (25°C). The measured data were fitted by the Marquardt method.

The results are shown in Tables 1-3.

The polyion complex particles in the compositions according to Examples 1-1 to 1-6 was small such that they were nano-size, while the size of the particle in the compositions according to Comparative Examples 1-1 to 1-13 could not be measured due to the presence of agglomerates.

(Summary)

Nanoparticles of polyion complex were obtained when the Polycation/Polyanion Ratio was greater than 0.3 and less than 0.8, and the Polycation/(Polycation+ Low Mw Anion) Ratio was greater than 0.2 and less than 0.5.

The particle size of the polyion complex particle was from about 30 nm to about 700 nm (cf. Ex.1-1 to Ex. 1-6).

When the Polycation/Polyanion Ratio was 0.3 or less or 0.8 or more, and/or when the Polycation/(Polyanion+Low Mw Anion) Ratio was 0.2 or less or 0.5 or more, agglomerates were formed, and polyion complex nanoparticles were not obtained (cf. Comp. Ex.1-1 to Com. Ex.1-13).

Examples 2-1 to 2-6 and Comparative Examples 2-1 to 2-2

[Preparation]

Compositions according to Examples 2-1 to 2-6 and Comparative Examples 2-1 to 2-2 were prepared by mixing the ingredients shown in Table 4. The amount of each ingredient used in the above preparations are shown in Table 4. The numerical values for the amounts of the ingredients shown in Table 4 are all based on “% by weight” as raw materials.

[Evaluations]

(Charge Concentration)

Charge Concentration [mmol/g] = (number of charged or chargeable sites of molecule)/ (molecular weight of molecule with counter ion if present) wherein if the molecule is in the form of a polymer, the molecule means a repeating unit of the polymer.

Please refer to the “Charge Concentration” column in Table 4. The values in the “Charge Concentration” column are absolute values.

(Polycation)

The results are shown in the “Polycation” line in Table 4.

(Polyanion)

The results are shown in the “Polyanion” line in Table 4.

(Low Mw Anion)

The results are shown in the “Low Mw Anion” line in Table 4.

(Polycation/Polyanion Ratio)

The results are shown in the “Polycation/Polyanion Ratio” line in Table 4.

{Polycation/(Polyanion+Low Mw Anion) Ratio}

The results are shown in the “Polycation/(Polyanion+Low Mw Anion) Ratio” line in Table 4.

(Appearance)

The appearance of each of the compositions according to Examples 2-1 to 2-6 and Comparative Examples 2-1 to 2-2 were visually observed. The results of the visual observation were categorized as follows.

U: Uniform (the appearance was uniform)

SA: Some Agglomerate (the appearance was slightly non-uniform due to some agglomerates) A: Agglomerate (the appearance was non-uniform due to agglomerates)

The results are shown in Table 4.

The compositions according to Examples 2-1 to 2-4 and Comparative Example 2-1 had uniform appearance, while the composition according to Comparative Example 2-2 had non- uniform appearance due to agglomerates present in the composition.

The compositions according to Examples 2-5 and 2-6 included some agglomerates. However, the uniformity thereof was acceptable.

(Transparency)

The turbidity of each of the compositions according to Examples 2-1 to 2-6 and Comparative Example 2-1 was measured at room temperature (25°C) by using a trubidimeter (2100Q portable, Hach Company). The turbidity of the composition according to Comparative Example 2-2 could not be measured because it was too high and out of the detectable range of turbidity.

The results are shown in Table 4 as “NTU”. The smaller the NTU value is, the more transparent the composition is.

The compositions according to Examples 2-1 to 2-6 were transparent. The composition according to Comparative Example 2-1 was translucent. The composition according to Comparative Example 2-2 was opaque.

(Particle Size)

A particle size analyzer (Dynamic Light Scattering, ELSZ2000, Otsuka) was used to determine the size of the particle in the compositions according to Examples 2-1 to 2-6 and Comparative Example 2-1 at room temperature (25°C). The measured data were fitted by the Marquardt method. The particle size of the particles in the composition according to Comparative Example 2-2 was not available.

The results are shown in Table 4. The size of the polyion complex particles in the compositions according to Examples 2-1 to 2- 4 as well as Examples 2-5 and 2-6 was small such that they were nano-size, while the size of the particle in the composition according to Comparative Examples 2-1 was large.

(Summary)

When the charge concentration of the polyanion was 2.04 mmol/g, nanoparticles could not be obtained (cf. Comp. Ex. 2-1).

On the other hand, nanoparticles were obtained, when the charge concentration of the polyanion is greater than 2.04 mmol/g (cf. Ex.2-1 to Ex. 2-4).

When the charge concentration of the polyanion was 5.00 mmol/g or more, nanoparticles were obtained, although some agglomerates were also formed (cf. Ex. 2-5 and Ex. 2-6).

When the charge concentration of the polyanion was 10.64 mmol/g, agglomerates were formed (cf. Comp. Ex. 2-2).

Examples 3-1 and 3-2, and Comparative Example 3-1

[Preparation]

Compositions according to Examples 3-1 and 3-2, and Comparative Examples 3-1 were prepared by mixing the ingredients shown in Table 5. The amount of each ingredient used in the above preparations are shown in Table 5. The numerical values for the amounts of the ingredients shown in Table 5 are all based on “% by weight” as raw materials.

Table 5

U: Uniform, A: Agglomerates, NT: Not Tested

[Evaluations]

(Charge Concentration)

Please refer to the “Charge Concentration” column in Table 5. The values in the “Charge Concentration” column are absolute values.

(Polycation)

The amount of cations of a cationic polymer was determined by multiplying the charge concentration of the cationic polymer with the amount of the cationic polymer. The results are shown in the “Polycation” line in Table 5.

(Polyanion)

The results are shown in the “Polyanion” line in Table 5.

(Low Mw Anion)

The results are shown in the “Low Mw Anion” line in Table 5.

(Polycation/Polyanion Ratio)

The results are shown in the “Polycation/Polyanion Ratio” line in Table 5.

{Polycation/(Polyanion+Low Mw Anion) Ratio}

The results are shown in the “Polycation/(Polyanion+Low Mw Anion) Ratio” line in Table 5.

(Appearance)

The appearance of each of the compositions according to Example 3-1 and 3-2, and Comparative Example 3-1 were visually observed. The results of the visual observation were categorized as follows.

U: Uniform (the appearance was uniform)

A: Agglomerates (the appearance was not uniform due to agglomerates)

The results are shown in Table 5.

The compositions according to Examples 3-1 and 3-2 had uniform appearance, while the composition according to Comparative Example 3-1 had non-uniform appearance due to agglomerates present in the composition. (Transparency)

The turbidity of each of the compositions according to Examples 3-1 and 3-2 was measured at room temperature (25°C) by using a trubidimeter (2100Q portable, Hach Company).

The results are shown in Table 5 as “NTU”. The smaller the NTU value is, the more transparent the composition is.

The compositions according to Examples 3-1 and 3-2 were transparent, while the composition according to Comparative Example 3-1 was not transparent, and the turbidity thereof was therefore not tested.

(Particle Size)

A particle size analyzer (Dynamic Light Scattering, ELSZ2000, Otsuka) was used to determine the size of the particle in the compositions according to Examples 3-1 and 3-2 at room temperature (25 °C). The measured data were fitted by the Marquardt method.

The results are shown in Table 5.

The polyion complex particles in the compositions according to Examples 3-1 and 3-2 was small such that they were nano-size, while the size of the particle in the compositions according to Comparative Example 3-1 could not be measured due to the presence of agglomerates.

(Summary)

When the charge concentration of the polycation is 0.71 mmol/g, agglomerates were formed, and nanoparticles could not be obtained (cf. Comp. Ex.3-1).

Nanoparticles were obtained, when the charge concentration of the polycation is greater than 0.71 mmol/g (Ex. 3-1 and Ex. 3-2).

Examples 4-1 to 4-3

[Preparation]

Compositions according to Examples 4-1 to 4-3 were prepared by mixing the ingredients shown in Table 6. The amount of each ingredient used in the above preparations are shown in Table 6. The numerical values for the amounts of the ingredients shown in Table 6 are all based on “% by weight” as raw materials. Table 6

U: Uniform

[Evaluations]

(Charge Concentration)

Please refer to the “Charge Concentration” column in Table 6. The values in the “Charge Concentration” column are absolute values.

(Polycation)

The amount of cations of a cationic polymer was determined by multiplying the charge concentration of the cationic polymer with the amount of the cationic polymer. The results are shown in the “Polycation” line in Table 6.

(Polyanion)

The results are shown in the “Polyanion” line in Table 6.

(Low Mw Anion)

The results are shown in the “Low Mw Anion” line in Table 6.

(Polycation/Polyanion Ratio)

The results are shown in the “Polycation/Polyanion Ratio” line in Table 6.

{Polycation/(Polyanion+Low Mw Anion) Ratio}

The results are shown in the “Polycation/(Polyanion+Low Mw Anion) Ratio” line in Table 6.

(Appearance)

The appearance of each of the compositions according to Example 4-1 to 4-3 were visually observed. The results of the visual observation were categorized as follows.

U: Uniform (the appearance was uniform)

A: Agglomerates (the appearance was not uniform due to agglomerates)

The results are shown in Table 6.

The compositions according to Examples 4-1 to 4-3 had uniform appearance.

(Transparency)

The turbidity of each of the compositions according to Examples 4-1 to 4-3 was measured at room temperature (25°C) by using a trubidimeter (2100Q portable, Hach Company).

The results are shown in Table 6 as “NTU”. The smaller the NTU value is, the more transparent the composition is.

The compositions according to Examples 4-1 to 4-3 were transparent.

(Particle Size)

A particle size analyzer (Dynamic Light Scattering, ELSZ2000, Otsuka) was used to determine the size of the particle in the compositions according to Examples 4-1 to 4-3 at room temperature (25°C). The measured data were fitted by the Marquardt method.

The results are shown in Table 6.

The polyion complex particles in the compositions according to Examples 4-1 to 4-3 was small such that they were nano-size.

(Summary)

Nanoparticles were obtained using any non-polymeric acid (cf. Ex.4-1 to Ex. 4-3).

Claims

1. A composition, preferably a cosmetic composition, and more preferably a cosmetic composition for keratin substance, comprising:

(a) at least one cationic polymer;

(b) at least one anionic polymer;

(c) at least one non-polymeric acid or salt thereof; and

(d) water wherein the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64mmol/g, and the (a) cationic polymer, the (b) anionic polymer, and the (c) non-polymeric acid or salt thereof is capable of forming at least one polyion complex particle with a particle size of less than 1000 nm.

2. The composition according to Claim 1, wherein the (a) cationic polymer is selected from (co)polyamines.

3. The composition according to Claim 1 or 2, wherein the (a) cationic polymer is selected from the group consisting of polylysine, chitosan, and a mixture thereof.

4. The composition according to any one of Claims 1 to 3, wherein the amount of the (a) cationic polymer(s) in the composition is from 0.001% to 2% by weight, preferably from 0.005% to 1.5% by weight, and more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.

5. The composition according to any one of Claims 1 to 4, wherein the (b) anionic polymer is selected from polysaccharides.

6. The composition according to any one of Claims 1 to 5, wherein the (b) anionic polymer is selected from the group consisting of hyaluronate, i-carrageenan, A- carrageenan, algin, chondroitin sulfate, pectin, and a mixture thereof.

7. The composition according to any one of Claims 1 to 6, wherein the amount of the (b) anionic polymer(s) in the composition is from 0.001% to 2% by weight, preferably from 0.005% to 1.5% by weight, and more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.

8. The composition according to any one of Claims 1 to 7 wherein the (c) non- polymeric acid has two or more pKa values.

9. The composition according to any one of Claims 1 to 7 wherein the (c) non- polymeric acid is selected from the group consisting of phytic acid, citric acid, lactic acid, and a mixture thereof.

10. The composition according to any one of Claims 1 to 9, wherein the amount of the

(c) non-polymeric acid(s) or salt(s) thereof in the composition is from 0.001% to 1% by weight, preferably from 0.005% to 0.5% by weight, and more preferably from 0.01% to 0.1% by weight, relative to the total weight of the composition.

11. The composition according to any one of Claims 1 to 10, wherein the amount of the

(d) water in the composition is from 60% to 97% by weight, preferably from 70% to 96% by weight, and more preferably from 80% to 95% by weight, relative to the total weight of the composition.

12. The composition according to any one of Claims 1 to 11, wherein the pH of the composition is from 3 to 9, preferably from 3.5 to 8.5, and more preferably from 4 to 8.

13. A cosmetic process for keratin substance, comprising applying to the keratin substance the composition according to any one of Claims 1 to 12; and drying the composition to form a cosmetic film on the keratin substance.

14. A use of

(a) at least one cationic polymer;

(b) at least one anionic polymer; and

(c) at least one non-polymeric acid or salt thereof wherein the ratio of the amount of cations of the (a) cationic polymer(s) to the amount of anions of the (b) anionic polymer(s) is more than 0.3 and less than 0.8, the ratio of the amount of cations of the (a) cationic polymer(s) to the sum of the amount of anions of the (b) anionic polymer(s) and the amount of anions of the (c) non-polymeric acid(s) or salt(s) thereof is more than 0.2 and less than 0.5, the charge concentration of the (a) cationic polymer is more than 0.71 mmol/g, and the charge concentration of the (b) anionic polymer is more than 2.04 mmol/g and less than 10.64 mmol/g, in a composition comprising (d) water, in order to forming at least one polyion complex particle comprising the (a) cationic polymer, the (b) anionic polymer, and the (c) non-polymeric acid or salt, or salt thereof with a particle size of less than 1000 nm.